Many different types of medical and surgical treatments require a mass of material to be implanted in the body. For example, in one type of procedure for treating urinary incontinence, material is delivered to radial sites about the urethra to bulk tissue around the urethra. In other procedures, materials, such as bulking materials, are implanted in the body to treat aneurysms and arteriovenous malformations (AVMs), for example.
One type of bulking material currently approved by the FDA is a mixture of a phosphate carrier and either collagen or fat. However, this type of material is absorbed in the body within about one year and sometimes needs to be reinjected into a patient periodically. Other materials, such as TEFLON and silicone, have been tested, but some of these materials may be capable of migrating to vital organs of the body, such as the brain or the lungs, and thereby harm a patient.